             (.generateWithRelativeTime rx-observable
               (math-vec (* update-interval-ms (or vx 0))
                         (* update-interval-ms (or vy 0)))
-              (fn [v] (> (dist-sq v) min-slide-speed-sq))
+              (fn [v] (> (vec-length-sq v) min-slide-speed-sq))
               dampen
               identity
               (constantly update-interval-ms))))))))


(def swipe-damping-factor 1)
(def min-slide-speed-sq 16)

(def max-radius 32)
(def min-radius 2)

        (.map (constantly :scroll-end)))))

(defn dampen [v]
  (let [length (vec-length v)]
    (vec-with-length v (- length swipe-damping-factor))))

(defn swipe-displacements-observable [manager svg]
